Magnetic door latch



Dec. 16, 1958 w. D. TEAGUE ET Al.

MAGNETIC DOOR LATCH 2 Sheets-SheefI 1 Filed March l2, 1952 JNVENTOR:

,Ma @Tra/Mery Dec. 16, 1958 W. D. TEAGUE ET AL MAGNETIC DOOR LATCH 2 Sheets-Sheet 2 JNVENToRs Lyme Filed March 12, 1952 MAGNnriC Doon LATCH Walter D. Teague, Annandale, N. J., and Robert H. En-

sign, Bronxville, N. Y., assignors, hy mesne assignments, to Whirlpool Corporation, a corporation of Delaware Application March 12, 1952, Serial No. 276,204

Claims. (Cl. 292-2515) The present invention relates to a door latch and more particularly to a latch operated by the magnetic force between relatively movable magnet and armature elements mounted on the door and cabinet of a refrigerator or the like.

Magnetic latches have heretofore been proposed for use on refrigerators, but in such prior art arrangements the relatively movable magnet and armature must be brought into direct contact with each other to latch the door in closed position on the cabinet. This is due to the inherent characteristics of a permanent magnet which produces little or no force on an armature when the latter is located only a short distance away from the magnet. When such a magnetic latch is used on a refrigerator cabinet, the yieldable sealing gasket opposes the closing of the door and sometimes prevents latching engagement of the armature with the magnet. Furthermore, after the armature and magnet have been engaged in such prior art devices, it is difficult to break the magnetic bond between the elements when the door is to be opened.

One of the objects of the present invention is to provide a magnetic latch having relatively movable cooperating elements on a door and cabinet so arranged as to insure latching engagement of the elements as the door is moved toward closing position.

Another object is to provide a magnetic latch of the type indicated having one of the magnet or armature elements biased to engage the other element at an angle and hinged for rocking movement by the magnetic force between the elements to positively move the door toward its fully closed position on the cabinet.

Another object is to provide a magnetic latch of the type indicated having the magnet or armature element on the door pivotally mounted for rocking movement relative to the other element on the cabinet to break the magnetic bond therebetween.

Another object is to provide a magnetic latch of the type indicated having one of the magnet and armature elements hinged to the door frame of a refrigerator cabinet and biased to project outwardly therefrom at an angle thereto and the other element yieldingly held in one position on the door but adapted to rock relative to the element on the cabinet to break the magnetic bond therebetween.

Still another object is to provide a magnetic latchof the type indicated which is of simple and compact construction, economical to manufacture and having an irnproved construction for concentrating the field of the` magnet to produce a maximum magnetic force on the armature.

These and other objects will become more apparent from the following description and drawings in which like reference characters denote like parts throughout the several views. It is to be expressly understood, however, that the drawings are for the purpose of illustration only and not a definition'of the limits of the invenatent tion, reference being had for this purpose to the appended claims. In the drawings:

Fig. 1 is a front elevational view of a refrigerator incorporating the magnetic latch of the present invention;

Fig. 2 is a sectional plan View of the latch showing the magnet assembly mounted on the cabinet and the armature assembly mounted on the door and the relationship of the elements when the door is latched in closed position on the cabinet;

Fig. 3 is a front elevational view of the magnet assembly showing a cylindrical magnet mounted on and having its forward end projecting through an opening in a hinged plate;

Fig. 4 is a front view of the armature assembly showing the armature mounted on pintles to rock about a central axis;

Fig. 5 is a sectional view of the latch in side elevation and showing the magnet on the cabinet biased to tilt outwardly toward the armature on the door;

Fig. 6 is a view similar to Fig. 5 showing the armature and magnet rocked into parallel relationship by the magnetic force between the elements to draw the door to its closed position on the cabinet; and

Fig. 7 is an enlarged view similar to Fig. 6 and showing the armature rocked relative to the plane of the magnet to unlatch the door.

Referring to Fig. 1 of the drawings, the invention is shown applied to a refrigerator 8 having a storage compartment 9 into which access may be had by a door 10 hinged at 11 to the front of the refrigerator. As shown the refrigerator 8 is of the full front door type in which the marginal portion 12 of the door overlaps the door frame 13 of the refrigerator cabinet around the entire periphery of the storage compartment 9. r

The refrigerator cabinet may be of any suitable construction and in the illustrated embodiment comprises an outer shell 14 and an inner shell or liner 15 with insulation 16 therebetween. Between the outer shell 14 and liner 15 at the front of the cabinet is an enclosing structure forming the door frame 13 including a door jamb 17 engageable by a gasket 18 on the door 10, later to be described in detail. The door jamb 17 is formed by folding the forward portion of the shell 14 inwardly and then rearwardly and outwardly in a close fold to produce a reenforced flange around the entire periphery of the shell. The remaining edge portion of the shell is then folded rearwardly and inwardly to provide a second flange 20 spaced rearwardly from the door jamb 17, see Fig. 2. A channel 21 has one flange 22 abutting and welded to the flange 20 of the cabinet shell, a web 23 abutting and welded to the side of the shell and a ange 24 projecting inwardly from the side of the shell. The channel 21 extends vertically throughout the height of the cabinet and the inner shell or liner 15 has ears 25 for mounting it on the flange 24 of the channel 21. As illustrated in Fig. 2, the ears 25 of the liner 15 are spaced from the flange 24 of the channel 21 by separators 26 of a heat insulating material such as rubber and the parts are connected together by screws 27 extending through the ears, spacers and flange of the channel. A trim strip 28 of any suitable shape has one edge projecting into the space between the door jamb 17 and ange 20 and its opposite end lies in a seat 29 at the edge of the inner shell or liner 15. The trim strip 28 may be formed of any suitable heat insulating material and fastened in position by any suitable means.

The door 10 also may be of any suitable construction and as illustrated comprises outer and inner walls 30 and 31. The outer wall 30 is a pressed metal sheet having its edge folded inwardly to provide a peripheral flange 32. The marginal portion 12 of the inner wall or panel 31 overlies the ange 32 and is connected thereto by a series of spaced screws 33. Gasket 18 has an inner flange or welt 34 compressed between the flange 32 and marginal portion 1,2 ofthe panel 31. The gasket properwlS eX- tends around the edge of the door panel 31 and overlies the inner yface, of the marginal portion 12 thereof. As illustrated, the gasket 13 is cored at 35 to adapt it to Yyield and has a ,series of longitudinal ribs 36vr for engaging the jambk17 of the door frame 13 to seal the joint therebetween when the door is closed. The space between the outer wall 34 andthe door panel '31 is lled with an insulating material as well understood in the art.

In accordancewith .the present invention, a magnetic latch is provided for retaining `the door in closed position on the cabinet of the refrigerator V`8. The magnetic latch comprises a magnet assembly and an armature assembly 41 with one of the assemblies mounted on the marginal portion l2 of the door and the other assembly mounted on the door frame 13 of the cabinet. Either the magnet or armature element of assembly 40 or 41 is hingedly mounted and biased to project at an angle to the plane of the door 12 and the other element is yieldingly mounted for rocking movement. Due to the inclination of the projecting element, the two parts of the latch engage each other before the door is fully closed to insure latching engagement of the elements by positioning the larmature in the magnetic field of the magnet. After the relatively movable elements of the latch are initially engaged, magnetic force draws the magnet and armature into parallel relationship which, in turn, positively moves the door 1t) toward the door frame 13 and compresses the gasket 18 therebetween.

In the illustrated embodiment, the magnet assembly 40 is mounted on the door frame 13 of the cabinet and the armature assembly 41 is mounted on the marginal portion 12 of the door 10. The magnet assembly 40 comprises a mounting plate 42 and a plate 43 hinged to swing in an opening 44 in the mounting plate. The mounting plate 42 is attached to a portion of the flange 22 of the reenforcing channel 21 by means of screws 45, see Figs. 5 to 7, and the plate 43 is connected to the mounting plate by a hinge 46, see Figs. 3 and 5. Hinged plate 43 carries a magnet 47 which may be of any suitable magnetized material such as that commercially known as Alnico or the like and may be of any suitable shape such as the cylindrical form as shown. A cylindrical pole piece 48 of soft iron is in magnetic contact with the magnet 47 and projects through an opening in hinged plate 43 with its forward end flush with the face of the plate and held in close but spaced relation thereto by a thin spacer 49 of any suitable non-magnetic material, see Fig. 2. The rearward end of the magnet 47 is supported by a U-shaped yoke 50 having its ends attached to the rear of the hinged plate 43 adjacent the top and bottom thereof, see Fig. 7. The yoke 5t) and plate 43 are of magnetic material and in magnetic contact with the end or pole of the magnet 47 opposite from the pole piece 48 thereby providing a magnetic path from one pole of the magnet to the other interrupted only by the non-magnetic spacer 49. Hinge 46 has one leaf 51 attached to the mounting plate 42 and the other leaf 52 connected to one of the arms yof the yoke 5t) with a suitable spacer block 53 therebetween. Due tothe overbalance of the magnet 47, pole piece 48 and yoke 50, at the rear of the hinge pin 46a, the hinged plate 43 is initially biased to project forwardlyv at an angle to the plane of the mounting plate 42 and door frame 13 as illustrated in Fig. 5. Depending from the lower arm of the yoke Sil is a bracket 54 having an adjustable push rod 55 projecting forwardly through au opening 56 in the mounting plate 42. The push rod 55 may be in the form of a screw having threaded engagement with the bracket 54 to adjust the position of its head 57 relative to the plane of the hinged plate 43 and the push rod may be locked in adjusted position by a lock nut 58 on its threaded portion. Thus, plate 43 is hinged, biased to project forwardly from the mounting plate 42 and provides a narrow gap in the magnetic path between it and pole piece 48. Rearward movement of hinged plate 43 is limited by the head 57 of push rod 55 which engages the front of mounting plate 42 when the hinged plate is parallel with the plane of the mounting plate, see Fig. 7.

The armature assembly 41 mounted on the door 10 comprises a block or armature 60 of magnetic material such as steel and having a rectangular flat face 61 for engagement with the front at faces of magnet 47 and hinged plate 43 surrounding the magnet. The sides of the armature block are provided with pintles 62 projecting into bearing pads or ears 63 on a mounting plate 64. The plate 64,'in turn, is yieldingly mounted on a plate 65 of a supporting structure by means of screws 66 and rubber bushings 67. The supporting structure also includes a bracket attached to plate 65 and having spaced arms 68 and 63a, Vsee Fig. 2, extending to engage the outer wall 34 of the door. The outer end of the plate 65 is attached to the flange 32 ofthe outer wall 30 of the door 10 by means of flathead screws 69 and the ends of the arms 68 and .63a of the bracket are attached to the outer wall 30 by screws 7i). The rectangular armature block 60 projects rearwardly through suitable openings in the plates 64 and 65V and its side-opposite the flat face 61 is attached to one end of a handle extension 71 by suitable screws 72. As shown most clearly in Fig. 7, the handle extension 71 is of bar stock formed to extend upwardly, thenioutwardly through an opening 73 in the outer wall 30 ofthe door ltl-and jthen'downwardly with its end connected to the lower end of a handle 74 by screws 75. A stud 76, illustrated in the form of a flat headed screw, projects from the plate, 64 through an opening in the upwardly directed portion of handle extension bar 71 and a spring '77 mounted on the stud acts between the bai and anadjustable abutment 78 on the stud. The spring 77 holds the upwardly directed `portion of the bar 71 againstV an. abutment 79 on plate 65 formed by the projecting end of one of the screws 66 but yields to permit movement of the baraway from the plate as the armature 6@ rocks on .the pintles 62 from the position illustrated in Fig. 5 to that illustrated in Fig. 7. When the bar 71 engages pin 79, the at face 61 of the armature 60 is parallel with the plane of the door 10 and door frame 13. A striker plate Sil'is mounted on the lower end of plate 64 in alignmentwith the head 57 of push rod 55 on .the hinged plate 43 of the magnet assembly 40. The invention having now been described in detail, the mode of operation is explained as follows.

For purposes of description let it be assumed that the door lil is in open position, food and other material has been inserted o-r removed from the storage compartment 9 and the door is about to be closed. Swinging movement of the door l@ toward the door frame 13 of the cabinet causes the armature block 60 to move toward the hinged plate 43 of the magnet assembly 4i) on the door frame 13. Due to the position of hinged plate 43 which projects outwardly from the plane of the door frame 13 as illustrated in Fig. 5, the at face 61 of armature 60 is brought into close proximity to and into the magnetic field of the magnet 47 before the door 10 is fully closed. The magnetic force existing between the magnet 47 and armature 69 tends to draw the two elements toward each other. Simultaneously, however, the striker pad 80 on the plate 64 of the armature assembly 41 engages the head 57 of the push rod 55 projecting forwardly from the magnet assembly 40. Thus, the magnetic force tending to draw the armature 66) toward the face of the magnet 47 rocks the depending hinged plate 43 rearwardly and draws the door 10 toward the vdoor frame 13 of the cabinet. As the armature 60 and hinged plate` 43 have cooperating flat faces this movement will continue until the `two faces are in parallel relationship and in direct contact-with each other. During such movement of the armature 60 and hinged'plate 43 into parallel relationship, the gap between the two faces decreases, which increases the magnetic force until the two faces contact, at which time a maximum magnetic holding force is produced. It will be apparent, therefore, that as the door approaches closing position on the door frame 13 of the cabinet, the magnetic force between the armature 60 and magnet 47 on the hinged plate 43 progressively increases and compresses the gasket 18 between the door 10 and door jamb 17 of the cabinet. Thus, the hinged and biased arrangement of plate 43 insures latching engagement with the armature 60 during a door closing operation and the cooperation of the relatively moving parts further acts to draw the door 10 to its nal closing position.

When the door 10 is to be opened the handle 74 at the exterior of the door is rocked downwardly and the motion is transmitted through the bar 71 against the action of spring 77 to rock the armature 60 on the pintles 62 with a mechanical advantage due to the lever action of the handle. Due to the flat face 61 of the armature 60, the armature tends to rock about its lower corner below the face of the pole 48, see Figs. 2 and 7. Such rocking movement of the armature 60 cams the armature 6i) away from the pole 48 and pries the door 10 away from the door frame 13 of the cabinet. The same rocking movement of the handle 74 also tends to swing the door 10 on its hinges 11 so that the combined forces facilitate the separation of the armature 60 from the magnet 47 and permit the door to be opened with ease. As soon as the armature 6l) is separated from the magnet and the door 1) starts swinging away from the door frame 13, the magnetic force progressively decreases because of the increase in the gap therebetween. The hinged plate 43 follows the door 10 outwardly from the position shown in Fig. 7 back to the inclined position illustrated in Fig. 5 so as to be in position for engagement by the armature 60 during the next door closing operation.

It will now be observed that the present invention provides a magnetic latch having relatively movable cooperating elements on a door and cabinet so arranged as to insure latching engagement of the elements. It will also be observed that the hinged arrangement of one of the elements of the magnetic latch draws the door into sealing engagement with the cabinet as the two elements of the latch are rocked into parallel relationship by magnetic force. It will also be observed that the magnetic latch construction of the present invention facilitates the breaking of the magnetic bond between the armature and magnet when it is desired to open the door. It will still further be observed that the latch of the present invention is of a simple and compact construction and economical to manufacture.

While only one form of the invention is herein illustrated and described, it will be understood that modifications may be made in the construction and arrangement of elements without departing from the spirit and scope of the invention. Therefore, without limitation in this respect, the invention is defined by the following claims.

We claim:

l. A magnetic latch for use with a cabinet having a movable door, said latch comprising relatively movable magnet and armature elements having cooperating faces, the face on each of the elements being flat over its entire area, one of the elements adapted to be mounted on the cabinet and the other element adapted to be mounted on the door, one of said elements being mounted so that its flat face projects forwardly at an acute angle to the flat face of the other element, to insure engagel ment of the elements before the door is fully closed, and said element having the forwardly projecting flat face being hinged to rock on its mounting by the magnetic force between the flat faces of the elements for moving the door to closed position on the cabinet.

2. A magnetic latch for use with a cabinet having a 6 door frame and a movable door, said latch comprising relatively movable magnet and armature elements, one of the elements adapted to be mounted on the door frame of the cabinet and the other element adapted to be mounted on the door, a hinge connecting one of said elements to its mounting to adapt it to rock thereon, means to bias the hinged element to project forwardly at an acute angle toward the other element to insure an initial engagement of the latching elements before the door is closed, and said elements having opposed surfaces arlranged to rock the hinged element as the surfaces are drawn into parallel relation by magnetic force to move the door to closed position on the cabinet.

3. A magnetic latch for use with a refrigerator cabinet of the type having a door frame forming a door opening, a swinging door for opening and closing the cabinet and having a marginal portion overlying the door frame, and said marginal portion having a gasket for engaging the door frame to seal the opening, the magnetic latch comprising a plate adapted to be hinged to the door frame and biased to project outwardly at an angle thereto, at least a portion of said plate being magnetized, and an armature adapted to be mounted on the door and having a flat face for cooperation with the magnetized plate, the magnetic force between the armature and hinged plate rocking the latter into parallel relationship with the at face of the armature to move the door toward the cabinet and to compress the gasket against the door frame.

4. A magnetic latch for use with a refrigerator cabinet of the `type having `a door frame forming a door opening, a swinging door for opening and closing the cabinet and having a marginal portion overlying the door frame, and said marginal portion having a gasket for engaging the door frame to sea-l the opening, the magnetic latch comprising a depending plate adapted to be hinged at its upper edge to the door frame, a magnet on the hinged plate and projecting rearwardly therefrom to tilt the plate at an angle `to the plane of the door frame, a push rod connected to the pivoted plate adapted `to be mounted below the magnet, a plate on the door and having an armature for engagement with the magnet, and a striker on the plate on the door for engaging the end of the push rod to rock the hinged plate as the armature is drawn toward the magnet by magnetic force.

5. A magnetic latch for use with a refrigerator cabinet of the type having a door frame forming a door opening and having a recess in one side thereof, a swinging door for opening and closing the cabinet and having a marginal portion overlying the door frame, and said marginal portion having a gasket for engaging the door frame to seal the door to the cabinet around the opening, the magnetic latch comprising a frame-plate adapted to be mounted on the door frame around the recess, a depending latch plate adapted to be hingedly connected to the frame plate at its upper edge, a yoke at the rear of the latch plate, a magnet mounted on the yoke with one end projecting through an opening in the latch plate and ush with the surface thereof, a spacer -of non-magnetic material between the magnet and latch plate, said magnet and yoke at the rear of the latch plate tilting the latter to project at an angle from the door frame, and an armature on the marginal portion of the door adapted to overlie the y end of the magnet and latch plate.

6. A magnetic latch for use with a cabinet having an opening and a hinged door for closing the opening, said magnetic latch comprising relatively movable elements adapted to be mounted on the cabinet and door, respectively, and having cooperating surfaces, one of the elements being a magnet and the other element being a magnetic armature, means for pivotally mounting the element on the door, said pivotal mounting having its axis located intermediate two opposite sides of the element, and a lever connected to the pivoted element to rock it about one side on the other ele-ment to break the magnetic bond between the contacting surfaces.

aseaesv 7. A magnetic latch for use with a refrigerator cabinet of the type .havingia door, frame ,forming a door opening anda door hinged for movement toward ,andaway from the door,` frame for openingandclosing the cabinet, said magnetic latch comprising elements adapted to be mounted on the cabinet and dooie respectively, andhavue mi cooperating faces, oneof the elements .comprising a masnet and a supporting: s tfructureproviding a magnetic path with a gapV on its face, the other element being of magetic material land over-lying saidoneelernent to bridge the gap in thefmagnetic path, means for pivotally mounting the element on the door, said pivotal mounting having its axis located intermediate two opposite sides of the element, and a lever connected to the pivoted element to rock it about one side on the other element to break the magnetic .bond between the contacting flat faces.

8. A magnetic latch for use with a cabinet having an opening and a door hinged Vfor swinging movement 'to open and close the cabinet, said magnetic latch comprising relatively movable magnet and armature elements with one of the elements. adapted to be kmounted ,on Vthe cabinet and the other e'lementadapted to vbe mounted on the door, said elements having contacting surfaces, the element on the cabinet .being hinged for rocking movement thereon, the element on the `door being pivtally mounted for rocking movement relativeto the element on the cabinet, and a lever connected to rock k,the element on the door to break the magnetic bond between the contacting surfaces of the elements.

9. `A magnetic latch for use with a refrigerator cabinet of the type having a door frame forming an opening, a door hinged to one side of the door frame for swinging movement to open and close the refrigerator cabinet, and a gasket on the door for engaging the door frame toseal the cabinet, said magnetic latch comprising a plate adapted to be hinged on the door frame and biased to hang at an angle thereto, said plate mounting a magnet having a pole piece extending therethrough but spaced therefrom, a magnetic armature adapted to be mounted on thedoor and having a at face adapted to overlie the pole piece of the magnet and a marginal `portion of the hinged plate surrounding the pole piece on the cabinet, means for pivotally mounting the armature for rocking movement about an axis intermediate two opposite sides, and a 'lever connected yto rock the pivoted armature relative tothe pole piece of the magnet on the cabinet to break the inag-k netic bond `between the contacting faces of the armature and plate..

10. -A lmagnetic latch for use with a refrigerator cabinet of the type having a door frame, ay door hinged to one side of the door frame for swinging movement to open or yclose they cabinet, and a gasket between the rvdoor and door frame for sealing the cabinet, said magnetic latch comprising a plate adapted to be hinged to the cabinet at its upper edge, a magnet having a pole piece projecting through the hinged plate `with non-magnetic material therebetween, said magnet and plate constituting an interrupted magnetic circuit and said .magnet biasing the plate to project at an angle from the door framea plate adapted to `be rigidly mounted on the door and having an arma ture of magnetic material pivotally kmounted thereon, a Y

lever at the exterior of the door and connected to the armature, a spring between the lever and plate on the `door for holding the face of the armatureparallel to the plane of ythe door frame engaged by the gasket, the magnetic force between the armature and hinged plate rocking the latter into parallel relationship tov compress the gasket between the door and door frame, and said lever being movable against the action of the spring to rock Ithe armature relative to the, hinged plate to break the magnetic bond therebetween.

' References Cited in the file of this patent UNITED STATES PATENTS 2,252,144 Taylor et al. Aug. 12, 1941 2,253,252 Smith Aug. 19, 1941 2,508,305 Teetor May `16, 1950 2,514,927 Bernhard July 11, 1950 2,519,435` `Byrd Allg. 22, 1950 2,673,111 iTeetor p Mar. 23, 1,954 2,673,755 Asp Mar. 30, 1954 2,690,922 Teetor Oct. 5, 1954 

